Generating Machining Directions for 5-axis NC Machining of Cycling Helmet’s Mold Components

  • Alan C. Lin
  • Mohammad Khoirul EffendiEmail author
Regular Paper


Mold components for producing a cycling helmet are one of the most complex parts encountered in 5-axis NC machining. One important factor namely machining direction is used not only for checking collision, but also for reducing machine setup and shaping surface with low curvature variations. This paper focuses on how to minimize the total number of machining direction in 5-axis NC machining of cycling helmet’s mold components. In the proposed method, the machining direction candidates are generated using a regular placement method. V-maps are also used to select the machining direction through cascade filter of V-maps. Genetic algorithm is also used in order to identify the initial machining direction. Moreover, blockage solver and agglomeration method are applied in sequence to update the machining direction results. Additionally, to evaluate the performance of the proposed method, a CAD model for the cycling helmet mold components is created and used as a model of implementation. The computational result shows that the CAD model can be machined using the minimum number of machining directions. A 5-axis NC machine is also used to really produce the mold components.


5-axis NC machining Visibility map Machining direction Genetic algorithm Plastic injection molding 

List of symbols


Normal vector


Visibility map


Machining direction


Genetic algorithm


Sum of square error


Cascade filter of V-maps



This project is sponsored in part by The Ministry of Science and Technology, Republic of China, Project Number MOST 106-2221-E-011-081.


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Copyright information

© Korean Society for Precision Engineering 2019

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringNational Taiwan University of Science and TechnologyTaipeiTaiwan

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